Automated External Defibrillators (AEDs) have improved survival of heart attack patients tremendously since their introduction. AEDs enable laypeople to diagnose and treat various life threatening arrhythmias, providing more life saving benefits than conventional traditional cardiopulmonary resuscitation (CPR) techniques. AEDs are now deployed in many public locations (e.g., schools, shopping malls, airports, etc.), as well as in workplaces. In 2006 the U.S. market alone for AEDs was estimated to be $300 million.